1. Field of the Invention
The present invention is related generally to the field of level indicators and more particularly to a sensor arrangement with which the level of a liquid in a container is identified using an ultrasound measured length.
2. Description of the Related Art
A known sensor for determining a liquid level in a container is essentially composed of four elements, namely a tubular housing that is provided with a fastening flange and includes an interior which is in communication with a surrounding space through lower and upper compensating openings. Secondly, the sensor is composed of a plurality of ultrasound measured lengths radially penetrating an interior of the tubular housing and having ultrasound transducers arranged in pairs in the housing wall. Thirdly, the sensor is comprised of electrical leads leading to the electrodes from the housing control; and fourthly, control and evaluation electronic circuit is included connected to the ultrasound measured lengths through the electrical leads. See, for example, U.S. Pat. No. 4,063,457. The manufacture of the known sensor is rather involved, and when used in a container of greatly agitated liquid, inaccurate indications can occur.
A further device for measuring the liquid level in a motor vehicle tank is also known which is also an indicator including a float as the encoder that is arranged in a vertical immersion pipe. To dampen the motion of the float particularly in greatly agitated liquid levels, a channel is arranged in the floor of the immersion pipe which connects the interior of the immersion pipe to the tank. The channel is shaped with oppositely directed turns or may be in the shape of a spiral. See, for example, German Patent No. 12 08 089.